1. Field of the Invention
The invention relates to a telescopic shaft and a steering system.
2. Description of Related Art
Japanese Patent Application Publication No. 2010-053943 proposes a telescopic shaft having a structure in which each of coil springs is disposed between a washer disposed at a distal end portion of an inner shaft, and a ball disposed in each of recessed grooves. In a telescopic shaft of Japanese Patent Application Publication No. 2009-197818, a movable washer, a spring plate, and a fixed washer are sequentially externally-fitted to a small-diameter shaft portion at a shaft end of a male shaft. A shaft end of the small-diameter shaft portion is subjected to crimping, and the crimped portion locks the fixed washer. The spring plate is received by the fixed washer, and urges the movable washer. The movable washer and the spring plate constitute a buffer element that buffers collision with a ball.
In JP 2010-053943 A, it is necessary to separately attach each of the plurality of coil springs that are independent of each other to the corresponding recessed groove such that the coil springs do not fall from the recessed grooves when the telescopic shaft is assembled. Thus, ease of assembly is poor. In JP 2009-197818 A, it is necessary to separately attach a plurality of components (the spring plate and the movable washer) as the buffer element when the telescopic shaft is assembled. Thus, ease of assembly is poor.